I have been using hydroponics to grow various herbs, lettuces, and other food plants for some time now. It is a great way to grow fresh veggies.

Recently I ventured into designing my own hydroponic systems – as you can see below – this is the test bed I have been using.

I also have been working on a few iterations on various sensors to automate the rig.

My intentions for the project is to make a closed loop system. Meaning that the lights (if indoors) and pump are powered by solar power. Reducing the operating costs.

I also plan to automate the system using sensors and various actors.

The system as it stands now is horizontal – the plan is to move it to a vertical system. Allowing more plants in a given foot print.

The pump is a 110V AC pump. Will move to a 24V DC Pump. This will make using solar more efficent as you will not need to convert DC to AC.

The current pump is controlled by a AC timer. That will be replaced with an Actor – so that timing and water flow can be controlled.

The Lights are 110V as well. To make them controllable – I am designing my own to again run off 24V DC.

Sensor Design

For the Sensors – I am using the ESP8266 – Wifi enabled MCU – using the Ardunio toolkit. The reason for the ESP8266 – is they are inexpensive and I don’t need the horse power of an ESP32.

The configuration is loaded though a JSON document VIA the serial port on new devices. The configuration has the wifi network, and all that fun stuff.

The device communicates to a local RabbitMQ server, running the MQTT plug-in.

The sensor information is sent in a JSON document.

Also communication with the sensor is also done through MQTT – as far as getting status and modifying other configuration parameters.

Future work will be finalizing the base sensor design – which will consist of the power supply. Sensors and other actors will be extensions – added VIA add-on boards.

The current test sensors I have deployed are using a temperature probe that send the temperature reading when there is a .5 change (configurable) in the reading. I have setup a machine running a Python program, that is subscribed to the Sensor Reading Topic – that records the tempature data to a CSV file.